Roulette

Roulette is a casino and gambling game. A croupier turns a round a roulette wheel which has 37 or 38 separately numbered pockets in which a ball must land in.

The main pockets are numbered from 1 to 36 alternate between red and black, but the pockets are not in numerical order around the wheel, and there are instances of consecutive numbers being the same color. There is also a green pocket numbered 0, and in most roulette wheels in the United States, but not in Europe, there is a second green pocket marked 00.

If a player bets on a single number and wins, the payout is 35:1, meaning that for each dollar bet, one wins an additional $35.00 (for example, if the bet is $5, the total winnings would be 5x35=$175). After determining winning wagers and paying them off, casinos commonly leave winning bets on the table. The player is not obliged to leave that bet down, but if removing it should wait until the glass pawn (or other similar marker) has first been removed by the croupier.

Other betting options, with lower payoffs, include bets on multiple numbers in various combinations or ranges, on all odd or all even numbers, or by color.

The first form of roulette was devised in 17th century France, by the mathematician Blaise Pascal, who was supposedly inspired by his fascination with perpetual motion devices. The game has been played in its current form since as early as 1796 in Paris. In 1842, fellow Frenchmen François and Louis Blanc added the "0" to the roulette wheel in order to increase house odds.

In the early 1800s, roulette was brought into the U.S. where, to further increase house odds, a second zero, "00", was introduced. (In some forms of early American roulette the double-zero was replaced by an American Eagle.) In the 1800s, roulette spread all over both Europe and the U.S., becoming one of the most famous and most popular casino games. Some call roulette the "King of Casino Games", probably because it was associated with the glamour of the casinos in Monte Carlo (François Blanc actually established the first casinos there).

A legend tells about François Blanc, who supposedly bargained with the devil to obtain the secrets of roulette. The legend is based on the fact that if you add up all the numbers on the roulette wheel (from 1 to 36), the resulting total is "666", which is the "Number of the Beast".

There are two types of roulette, American and European. The difference between the two is the number of 0's on the wheel. American roulette wheels have two "0's", zero and double-zero, which increase the house advantage to 5.3%. In European roulette there is only one zero, giving the house an advantage of 2.7%. This means that, in the long run, one loses money nearly twice as fast playing American roulette than European roulette.

The two versions also use chips differently. American roulette uses so-called "non-value" chips, meaning that all chips belonging to the same player are of the same value determined at the time of the purchase, and the player cashes in the chips at the roulette table. European roulette uses standard casino chips of differing values as bets, which can make the game more confusing for both the croupier and the players.

There is actually a third type of roulette wheel in use. It is a hybrid of the two versions described above, and is the only kind of wheel that is legal in the United Kingdom. This wheel has an American (English language) layout and a single zero. When a single-zero wheel is used in the United States, it is almost always this type.

Straight: a single number. The chip is placed entirely on this square and no other.

Split: a bet on two adjoining numbers, either on the vertical or horizontal (as in 14-17 or 8-9). The chip is placed on the edge between these numbers.

Street: a bet on three numbers on a single horizontal line. The chip is placed on the edge of the number at the left or the right, depending on the layout.

Corner (or square) : a bet on four numbers in a square layout (as in 11-12-14-15). The chip is placed at the horizontal and vertical intersection of these numbers.

Sixline (or 'sixaine') : a bet on two adjoining streets, with the chip placed at the corresponding intersection (as in 25-30).

Column: a bet on all 12 numbers on any of the three vertical lines (such as 1-4-7-10 on down to 34). The chip is placed on the space below the final number in this string.

The house average or house edge (also called the expected value) is the amount the player loses relative to a bet, on average. If a player bets on a single number in the American game there is a probability of 1/38 that the player receives 36 times the bet (35 times the bet plus the return of the bet itself), so the player ends up, on average, losing 5.26% on each bet.

Albert Einstein is reputed to have stated, "You cannot beat a roulette table unless you steal money from it."

And yet, the numerous even money bets in roulette have inspired many players over the years to attempt to beat the game by using one or more variations of a Martingale betting strategy, wherein the gamer doubles the bet after every loss, so that the first win would recover all previous losses, plus win a profit equal to the original bet. As the referenced article on Martingales points out, this betting strategy is fundamentally flawed in practice and the inevitable long-term consequence is a large financial loss.

Another strategy is the Fibonacci system, where bets are calculated according to the Fibonacci sequence. Regardless of the specific progression, no such strategy can statistically overcome the casino's advantage.

While not a strategy to win money, Los Angeles Times editor Andres Martinez described an enjoyable roulette betting method in his book on Las Vegas entitled "24/7". He called it the "dopey experiment". The idea is to divide one's roulette session bankroll into 35 units. This unit is bet on a particular number for 35 consecutive spins. Thus, if the number hits in that time, the gambler wins back the original bankroll and can play subsequent spins with house money. However, there is only a (1 - (37 / 38)35) * 100% = 60.68% probability of winning within 35 spins (assuming a double zero wheel with 38 pockets).

There is a common misconception that the green numbers are "house numbers" and that by betting on them one "gains the house edge." In fact, it is true that the house's advantage comes from the existence of the green numbers (a game without them would be statistically fair) however they are no more or less likely to come up than any other number.

One conceivable strategy would be to bet on the ball landing in a red space for a certain number of spins, for example, 38.

There are 18 red spaces on a roulette table with 38 total spaces. Dividing 18 by 38 yields a probability of landing on red of 47.37%. This probability can be used in a binomial distribution and made into an approximate standard normal distribution.

Doing so indicates that, if one were to spin the wheel 38 times, there is a 99% probability that the ball would land on red at least 10 times. There is an 83% probability that in 38 spins, the ball will land on red at least 15 times. Out of 38 spins, there's a 50% chance that 18 will be red.

However, the break-even point is 19 spins, since the bet on red is 1:1, and the probability of 19 red spins in 38 is only 37%. This indicates the difficulty of winning by only betting on red.

The results occur because, as indicated by the 18 divided by 38 equals 47.37% figure, the ball will land on red less than half the time. This percentage applied in the binomial and standard normal distributions creates the vast divide in probability from 18 red spins to 19 red spins out of 38 spins. Basically, it is very unlikely for anyone to spin much more than 18 red spins out of 38 spins.

There are two versions to this system, single dozen bets and double dozen bets. In the single dozen bet version, you use a progressively incrementing stake list starting from the casino table minimum, to the table maximum. The aim here is to use a single dozen bet to win before the stake list ends.

Many techniques are employed such as: betting on the same dozen to appear after two consecutive appearances, betting on the dozen that has appeared most in the last 15, 9, or 5 spins, betting on the dozen that, after a long absence of 7 or more spins, appears for the first time. The double dozen bet version uses two dozen bets and half the stake list size of the single dozen bet version.

In 2004, Ashley Revell of London sold all of his possessions; clothing included, and brought US$135,300 to the Plaza Hotel in Las Vegas and put it all on "Red" at the roulette table in a double-or-nothing bet. The ball landed on "Red 7" and Revell walked away with his net-worth doubled to $270,600.

In the 1942 film Casablanca, Rick's Café Americain has a trick roulette wheel. The croupier can cause it to land on 22 at will. Rick (Humphrey Bogart) urges a Bulgarian refugee with whose case he becomes sympathetic to put his last three chips on 22 and motions to the croupier to let him win. After the man's number dramatically comes up, Rick tells him to let it all ride on 22 and lets him win again.